Fermilab's International Affairs department has received the go-ahead from the Department of Energy to invite experimenters back from India's Tata Institute of Fundamental Research, closing an awkward chapter in the Lab's long history of attempting to practice physics without borders.

"The process is going on, and we have invited several people from Tata," said Roy Rubinstein, head of the International Desk. "We anticipate it will take some time to obtain visas, but I'm not aware of any serious problems so far."

A member of the Lab's DZero collaboration since 1990, the Tata Institute was hit by the sanctions imposed by President Clinton against India and Pakistan for those nations' testing of nuclear weapons in 1998.

The Tata Institute appeared on the original list of affected "entities" announced by the U.S. State Department on June 18, 1998; it was one of 51 entities removed from the list by the U.S. Commerce Department on December 16, 1999 in what was described as "a consensus decision by the Administration to more tightly focus the sanctions on those Indian entities most directly involved" in the weapons activities.

No Tata scientists were actually expelled from Fermilab. As Rubinstein explained, their scheduled stays ended while the Lab sought clarification of their status from DOE. Rubinstein was prevented from issuing any further invitations to them, until now.

But the sanctions have meant that, for more than 18 months, collaborators from the Tata Institute were unable to install and test more than $500,000 in scintillation counter equipment they had provided for the detector's muon system upgrades for Run II. They have essentially lost that opportunity, since much of the work has been completed by other members of the DZero collaboration in their absence. The sanctions also limited their opportunities for physics analysis of Run I data.

"The experience would have been valuable to the students and young colleagues at TIFR," wrote V.S. Narasimham, spokesperson for the Tata collaboration, responding to questions by e-mail.

The Hadron 13 conference was another casualty of the sanctions, and another that Narasimham felt personally. He was the convener of the 13th Topical Conference on Hadron Collider Physics held in Mumbai, India in January 1999.

Fermilab scientists, as members of a national laboratory operating on DOE funds, were banned from attending the conference, although their results were to have served as a primary focus of the conference. (Rajendran Raja of Fermilab gave his scheduled talk after paying his own way to the conference; see the accompanying story, "Principles had priority on passage to India.")

"The emphasis of the meeting being on results from the Tevatron, naturally the absence of people from Fermilab was greatly felt," Narasimham said. "To the credit of Fermilab scientists, however, their talks were quickly redistributed to some of their colleagues from universities who were not under such restrictions and who made sure that the results were presented."

Reacting to the Hadron 13 ban, Fermilab physicist Paul Grannis, a longstanding member of DZero, sent a petition signed by some two dozen scientists to Secretary of Energy Bill Richardson. The petition read in part: "Restriction of access of U.S. national laboratory scientists to open conferences is antithetical to the spirit of free scientific inquiry; is unprecedented in basic research over the past 50 years; and is wholly irrelevant to national security concerns."

Grannis and the DZero collaboration also sent three communications to the State Department; one about the conference, another asking for the sanctions to be lifted, and a third asking for Tata to be removed from the list. Grannis also noted that Secretary Richardson met with Deputy Secretary of State Strobe Talbott shortly before the Hadron 13 conference to plead for a removal of sanctions.

"The DOE was very supportive throughout," Grannis said, citing efforts by Peter Rosen, director of high energy and nuclear physics. "The DOE's heart was surely in the right place."

There was, however, the "flag flap" at Fermilab. Shortly after the sanctions were announced, the Lab was advised through DOE channels to remove the flag of India from the row of flagpoles in front of Wilson Hall. John Peoples, the Lab's director at the time, said he wasn't quite sure how to react, because of conflicting advisories as time went on. But the flag has remained down.

"One thing I suggested was that we take down all the international flags," said Peoples, who along with Grannis emphasized the Lab's history of internationalism by citing the continuing participation of experimenters from the Soviet Union throughout the Cold War days. Peoples noted that both the Soviet presence and the Tata absence stemmed from decisions at the highest levels of government, with the attendant complexities of putting those decisions into action. He recalled, for example, that the primary duties of one Soviet "scientist" at Fermilab, whom everyone surmised to be a KGB agent, consisted of driving the Soviet scientists' wives on shopping trips in the contingent's official vehicle, a VW Microbus.

"Paul Grannis and our International Affairs people really carried the ball on getting this [Tata] issue turned around," Peoples said, "and fortunately, Secretary Richardson is very much an internationalist."

The Internet is also very much an internationalist, offering communication that was not as satisfactory as personal interaction, but highly effective in keeping channels open. Narasimham said the collaboration with DZero would have been "hopeless" without Internet communication.

"The collaboration obviously went on," Grannis said. "We just had to use e-mail and neutral territory. During the time of the sanctions, our Indian colleagues completed physics analysis, we discussed them, argued over them, finalized them and submitted them for publication."

Tata is also a major collaborator on the US/CMS project for the Large Hadron Collider at CERN, the European particle physics laboratory in Geneva, Switzerland. Fermilab's Dan Green, the US/CMS project manager, couldn't travel to India. He had to hold a major Engineering Design Review at CERN.

"There was no way to go [to Tata] and kick the tires," Green said. "We met at CERN. I had personal difficulties with e-mail, and several times had to resort to sending e-mail to CMS in CERN to be routed to Tata as a third party."

In summary, Grannis said the sanctions "did not make us look good in the international community." But he felt that most other scientists perceived American scientists as fighting against the sanctions, and Narasimham was gratified that "many scientists and scientific institutions tried to intervene on our behalf."

Narasimham plans to return to Fermilab next summer; some Tata scientists will precede him, and the collaboration is planning a computer farm to generate Monte Carlo simulation data for DZero results in Run II. The collaboration has survived

"I think the sanctions were unwarranted, certainly in their application to TIFR and to our collaboration with DZero," he said. "But this has nothing to do with science, and it did not in any way affect our interest in the experiment."